The present invention relates to a conveyor system and roller assembly that is particularly applicable for use in a multi-chamber washer and shall be described with reference thereto. It being understood, however, that a conveyor system or roller assembly according to the present invention may find advantageous application in other applications.
A multi-chamber washer is generally comprised of several different chambers that are aligned side-by-side. Each chamber has a specific purpose, such as washing, rinsing, or drying a load.
Objects washed within a multi-chamber washer are typically contained within an open basket or tray. A conveyor system is provided within the washer to move the basket or tray from one chamber to another. The conveyor system typically extends through the adjacent chambers within the washer to convey a basket or rack to the respective chambers.
Conveyor systems comprised of driven rollers have been used to convey the baskets or trays through a multi-chamber washer. One problem with such conveyor systems is maintaining a sufficient driving force between the baskets and the rollers. In this respect, different types of baskets may be used within the multi-chamber washers. Baskets having a base formed of plastic materials are often used in such washers to reduce noise during the conveying, i.e., indexing, of the baskets. Plastic material also makes it easier to control the friction coefficient between the baskets and the drive rollers. Other manufacturers form baskets of stainless steel material. Stainless steel racks are more easily cleaned during the washing process and are able to heat more quickly because of the higher coefficient of thermal conduction.
It is also known to form the conveyor rollers of a plastic or metal material. As indicated above, rollers formed of plastic material can provide a better coefficient of friction between the roller and the basket and, likewise, help reduce noise during the conveying, indexing process. However, as noted above, plastic rollers are more difficult to clean, as compared to metal rollers. Metal conveyor rollers are preferred because of the ability to clean such rollers during the washing process, as well as their durability. However, maintaining adequate driving force between a metal roller and a metal frame of a basket can be difficult, particularly in wet environments that would be encountered within the washer. Similarly, the friction coefficient between a metal roller and a metal basket will vary depending upon the weight of the basket and the articles therein.
The present invention overcomes these and other problems and provides a roller assembly for a conveyor system having improved frictional, driving characteristics.